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    <meta charset="UTF-8" />
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    <title>Document</title>
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  <body>
    年龄:<input type="text" /> <button class="prev">上一步</button
    ><button>完成注册</button>
    <script>
      document.querySelector(".prev").onclick = function () {
        window.location.href = "register1.html";
      };
    </script>
  </body>
</html>
